Capacity allocation and contention resolution in a photonic slot routing all-optical WDM mesh network

Photonic slot routing (PSR) has been proposed as an approach to implement an all-optical packet-switched network in a manner which is scalable and not overly complex. In PSR, packets are transmitted within a basic transport unit referred to as a photonic slot. The photonic slot is fixed in length and spans multiple wavelengths. Each photonic slot is routed through the network as a single entity; thus, individual wavelengths do not need to be multiplexed or demultiplexed at intermediate nodes through which the photonic slot is traversing. When implementing PSR in a mesh environment, a number of significant issues must be addressed. Two such issues are fairness and contention resolution. In this study, we propose a novel approach for allocating capacity on each link in a fair manner, and we investigate various approaches, such as buffering and deflection, for handling contention. We develop an analytical model to evaluate the performance of such networks, and validate the analysis through simulation. It is shown that the proposed capacity allocation approach can significantly reduce contention in the network and provide a fair allocation of bandwidth to each source-destination pair.